Olokele Gulch Bluegrass: Hawaii’s Critically Endangered Native Grass
Meet Olokele Gulch bluegrass (Poa mannii), one of Hawaii’s rarest native grasses that’s teetering on the edge of extinction. This perennial grass species is so rare that you’re more likely to spot a Hawaiian monk seal sunbathing on your lawn than find this elusive plant in the wild. But before you start planning your garden around this unique Hawaiian native, there’s something crucial you need to know.
A Grass in Crisis
Olokele Gulch bluegrass isn’t just rare—it’s critically imperiled with a Global Conservation Status of S1, meaning there are typically five or fewer occurrences remaining in the wild. In the United States, this grass holds the sobering designation of Endangered. With fewer than 1,000 individuals likely remaining, this species is hanging on by a thread.
Where in the World?
This endemic Hawaiian grass calls the islands home, with its name giving away its specific connection to the Olokele Gulch area. As a true Hawaiian native, it evolved in isolation over millions of years, making it uniquely adapted to Hawaii’s specific environmental conditions.
Why You Shouldn’t Plant This Grass (Yes, Really!)
Here’s where things get serious, fellow gardeners. While we typically encourage planting native species, Olokele Gulch bluegrass is the exception to this rule. Here’s why:
- It’s critically endangered: Every plant in the wild is precious for the species’ survival
- Illegal collection: Removing plants from their natural habitat could be illegal and harmful to wild populations
- Unknown cultivation requirements: We simply don’t know enough about successfully growing this grass outside its native environment
- Conservation priority: Efforts should focus on protecting existing wild populations rather than cultivation
What We Know (And Don’t Know)
As a perennial grass, Olokele Gulch bluegrass is part of the graminoid family—the grass and grass-like plants that include true grasses, sedges, and rushes. It has a facultative wetland status in Hawaii, meaning it can survive in both wetland and non-wetland conditions, giving it some flexibility in where it can grow.
Unfortunately, due to its rarity, many details about this grass remain mysterious. We don’t have clear information about its specific growing conditions, propagation methods, wildlife benefits, or even its exact appearance and size. This knowledge gap highlights just how endangered this species has become.
How You Can Help (Without Planting It)
While you can’t add this grass to your garden, you can still support its conservation:
- Support conservation organizations: Donate to groups working to protect Hawaiian native plants
- Choose other native Hawaiian grasses: Plant less endangered native species that provide similar ecological benefits
- Spread awareness: Share information about Hawaii’s endangered plants with fellow gardeners
- Respect wild areas: When hiking in Hawaii, stay on designated trails and never collect plants
Native Alternatives for Your Hawaiian Garden
If you’re gardening in Hawaii and want to support native biodiversity, consider these less endangered native grass alternatives that can provide similar ecological benefits without contributing to a species’ decline. Consult with local native plant societies or botanical gardens for recommendations on native grasses that are appropriate for cultivation.
A Call for Conservation
Olokele Gulch bluegrass serves as a stark reminder of what we stand to lose when native ecosystems are disrupted. While we can’t invite this particular grass into our gardens, we can honor its existence by supporting conservation efforts and making thoughtful choices about the plants we do grow.
Sometimes the best way to love a plant is to leave it alone—and in the case of Poa mannii, that’s exactly what this critically endangered species needs from us.
